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Shin KC, Ali Moussa HY, Park Y. Cholesterol imbalance and neurotransmission defects in neurodegeneration. Exp Mol Med 2024; 56:1685-1690. [PMID: 39085348 PMCID: PMC11371908 DOI: 10.1038/s12276-024-01273-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 08/02/2024] Open
Abstract
The brain contains the highest concentration of cholesterol in the human body, which emphasizes the importance of cholesterol in brain physiology. Cholesterol is involved in neurogenesis and synaptogenesis, and age-related reductions in cholesterol levels can lead to synaptic loss and impaired synaptic plasticity, which potentially contribute to neurodegeneration. The maintenance of cholesterol homeostasis in the neuronal plasma membrane is essential for normal brain function, and imbalances in cholesterol distribution are associated with various neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and Huntington's disease. This review aims to explore the molecular and pathological mechanisms by which cholesterol imbalance can lead to neurotransmission defects and neurodegeneration, focusing on four key mechanisms: (1) synaptic dysfunction, (2) alterations in membrane structure and protein clustering, (3) oligomers of amyloid beta (Aβ) protein, and (4) α-synuclein aggregation.
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Affiliation(s)
- Kyung Chul Shin
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Houda Yasmine Ali Moussa
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Yongsoo Park
- Neurological Disorders Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar.
- College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar.
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2
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Tarutani A, Adachi T, Akatsu H, Hashizume Y, Hasegawa K, Saito Y, Robinson AC, Mann DMA, Yoshida M, Murayama S, Hasegawa M. Ultrastructural and biochemical classification of pathogenic tau, α-synuclein and TDP-43. Acta Neuropathol 2022; 143:613-640. [PMID: 35513543 PMCID: PMC9107452 DOI: 10.1007/s00401-022-02426-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 04/12/2022] [Accepted: 04/23/2022] [Indexed: 12/20/2022]
Abstract
Intracellular accumulation of abnormal proteins with conformational changes is the defining neuropathological feature of neurodegenerative diseases. The pathogenic proteins that accumulate in patients' brains adopt an amyloid-like fibrous structure and exhibit various ultrastructural features. The biochemical analysis of pathogenic proteins in sarkosyl-insoluble fractions extracted from patients' brains also shows disease-specific features. Intriguingly, these ultrastructural and biochemical features are common within the same disease group. These differences among the pathogenic proteins extracted from patients' brains have important implications for definitive diagnosis of the disease, and also suggest the existence of pathogenic protein strains that contribute to the heterogeneity of pathogenesis in neurodegenerative diseases. Recent experimental evidence has shown that prion-like propagation of these pathogenic proteins from host cells to recipient cells underlies the onset and progression of neurodegenerative diseases. The reproduction of the pathological features that characterize each disease in cellular and animal models of prion-like propagation also implies that the structural differences in the pathogenic proteins are inherited in a prion-like manner. In this review, we summarize the ultrastructural and biochemical features of pathogenic proteins extracted from the brains of patients with neurodegenerative diseases that accumulate abnormal forms of tau, α-synuclein, and TDP-43, and we discuss how these disease-specific properties are maintained in the brain, based on recent experimental insights.
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Affiliation(s)
- Airi Tarutani
- Department of Brain and Neuroscience, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Tadashi Adachi
- Division of Neuropathology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Tottori, 683-8503, Japan
| | - Hiroyasu Akatsu
- Department of Neuropathology, Choju Medical Institute, Fukushimura Hospital, Aichi, 441-8124, Japan
- Department of Community-Based Medical Education, Nagoya City University Graduate School of Medical Sciences, Aichi, 467-8601, Japan
| | - Yoshio Hashizume
- Department of Neuropathology, Choju Medical Institute, Fukushimura Hospital, Aichi, 441-8124, Japan
| | - Kazuko Hasegawa
- Division of Neurology, National Hospital Organization, Sagamihara National Hospital, Kanagawa, 252-0392, Japan
| | - Yuko Saito
- Department of Neuropathology, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015, Japan
- Department of Pathology and Laboratory Medicine, National Center Hospital, National Center of Neurology and Psychiatry, Tokyo, 187-8551, Japan
| | - Andrew C Robinson
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience and Experimental Psychology, Salford Royal Hospital, The University of Manchester, Salford, M6 8HD, UK
| | - David M A Mann
- Faculty of Biology, Medicine and Health, School of Biological Sciences, Division of Neuroscience and Experimental Psychology, Salford Royal Hospital, The University of Manchester, Salford, M6 8HD, UK
| | - Mari Yoshida
- Department of Neuropathology, Institute for Medical Science of Aging, Aichi Medical University, Aichi, 480-1195, Japan
| | - Shigeo Murayama
- Department of Neuropathology, Tokyo Metropolitan Institute of Gerontology, Tokyo, 173-0015, Japan
- Brain Bank for Neurodevelopmental, Neurological and Psychiatric Disorders, United Graduate School of Child Development, Osaka University, Osaka, 565-0871, Japan
| | - Masato Hasegawa
- Department of Brain and Neuroscience, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo, 156-8506, Japan.
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3
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Limorenko G, Lashuel HA. Revisiting the grammar of Tau aggregation and pathology formation: how new insights from brain pathology are shaping how we study and target Tauopathies. Chem Soc Rev 2021; 51:513-565. [PMID: 34889934 DOI: 10.1039/d1cs00127b] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Converging evidence continues to point towards Tau aggregation and pathology formation as central events in the pathogenesis of Alzheimer's disease and other Tauopathies. Despite significant advances in understanding the morphological and structural properties of Tau fibrils, many fundamental questions remain about what causes Tau to aggregate in the first place. The exact roles of cofactors, Tau post-translational modifications, and Tau interactome in regulating Tau aggregation, pathology formation, and toxicity remain unknown. Recent studies have put the spotlight on the wide gap between the complexity of Tau structures, aggregation, and pathology formation in the brain and the simplicity of experimental approaches used for modeling these processes in research laboratories. Embracing and deconstructing this complexity is an essential first step to understanding the role of Tau in health and disease. To help deconstruct this complexity and understand its implication for the development of effective Tau targeting diagnostics and therapies, we firstly review how our understanding of Tau aggregation and pathology formation has evolved over the past few decades. Secondly, we present an analysis of new findings and insights from recent studies illustrating the biochemical, structural, and functional heterogeneity of Tau aggregates. Thirdly, we discuss the importance of adopting new experimental approaches that embrace the complexity of Tau aggregation and pathology as an important first step towards developing mechanism- and structure-based therapies that account for the pathological and clinical heterogeneity of Alzheimer's disease and Tauopathies. We believe that this is essential to develop effective diagnostics and therapies to treat these devastating diseases.
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Affiliation(s)
- Galina Limorenko
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Federal de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, École Polytechnique Federal de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
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Sallaberry CA, Voss BJ, Majewski J, Biernat J, Mandelkow E, Chi EY, Vander Zanden CM. Tau and Membranes: Interactions That Promote Folding and Condensation. Front Cell Dev Biol 2021; 9:725241. [PMID: 34621743 PMCID: PMC8491580 DOI: 10.3389/fcell.2021.725241] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/31/2021] [Indexed: 12/15/2022] Open
Abstract
Tau misfolding and assembly is linked to a number of neurodegenerative diseases collectively described as tauopathies, including Alzheimer’s disease (AD) and Parkinson’s disease. Anionic cellular membranes, such as the cytosolic leaflet of the plasma membrane, are sites that concentrate and neutralize tau, primarily due to electrostatic interactions with tau’s microtubule binding repeat domain (RD). In addition to electrostatic interactions with lipids, tau also has interactions with membrane proteins, which are important for tau’s cellular functions. Tau also interacts with lipid tails to facilitate direct translocation across the membrane and can form stable protein-lipid complexes involved in cell-to-cell transport. Concentrated tau monomers at the membrane surface can form reversible condensates, change secondary structures, and induce oligomers, which may eventually undergo irreversible crosslinking and fibril formation. These β-sheet rich tau structures are capable of disrupting membrane organization and are toxic in cell-based assays. Given the evidence for relevant membrane-based tau assembly, we review the emerging hypothesis that polyanionic membranes may serve as a site for phase-separated tau condensation. Membrane-mediated phase separation may have important implications for regulating tau folding/misfolding, and may be a powerful mechanism to spatially direct tau for native membrane-mediated functions.
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Affiliation(s)
- Chad A Sallaberry
- Department of Chemistry & Biochemistry, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Barbie J Voss
- Department of Chemistry & Biochemistry, University of Colorado Colorado Springs, Colorado Springs, CO, United States
| | - Jaroslaw Majewski
- Division of Molecular and Cellular Biosciences, National Science Foundation, Alexandria, VA, United States.,Department of Chemical & Biological Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM, United States.,Theoretical Biology and Biophysics Division, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Jacek Biernat
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Eckhard Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Center of Advanced European Studies and Research (CAESAR) Center, Bonn, Germany.,Department of Neurodegenerative Disease and Geriatric Psychiatry, Medical School, University of Bonn, Bonn, Germany
| | - Eva Y Chi
- Department of Chemical & Biological Engineering, Center for Biomedical Engineering, The University of New Mexico, Albuquerque, NM, United States
| | - Crystal M Vander Zanden
- Department of Chemistry & Biochemistry, University of Colorado Colorado Springs, Colorado Springs, CO, United States
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Barracchia CG, Tira R, Parolini F, Munari F, Bubacco L, Spyroulias GA, D’Onofrio M, Assfalg M. Unsaturated Fatty Acid-Induced Conformational Transitions and Aggregation of the Repeat Domain of Tau. Molecules 2020; 25:molecules25112716. [PMID: 32545360 PMCID: PMC7321374 DOI: 10.3390/molecules25112716] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/07/2020] [Accepted: 06/10/2020] [Indexed: 12/20/2022] Open
Abstract
Background: The intrinsically disordered, amyloidogenic protein Tau associates with diverse classes of molecules, including proteins, nucleic acids, and lipids. Mounting evidence suggests that fatty acid molecules could play a role in the dysfunction of this protein, however, their interaction with Tau remains poorly characterized. Methods: In a bid to elucidate the association of Tau with unsaturated fatty acids at the sub-molecular level, we carried out a variety of solution NMR experiments in combination with circular dichroism and fluorescence measurements. Our study shows that Tau4RD, the highly basic four-repeat domain of Tau, associates strongly with arachidonic and oleic acid assemblies in a high lipid/protein ratio, perturbing their supramolecular states and itself undergoing time-dependent structural adaptation. The structural signatures of Tau4RD/fatty acid aggregates appear similar for arachidonic acid and oleic acid, however, they are distinct from those of another prototypical intrinsically disordered protein, α-synuclein, when bound to these lipids, revealing protein-specific conformational adaptations. Both fatty acid molecules are found to invariably promote the self-aggregation of Tau4RD and of α-synuclein. Conclusions: This study describes the reciprocal influence that Tau4RD and fatty acids exert on their conformational states, contributing to our understanding of fundamental aspects of Tau/lipid co-assembly.
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Affiliation(s)
- Carlo Giorgio Barracchia
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Roberto Tira
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Francesca Parolini
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Francesca Munari
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Luigi Bubacco
- Department of Biology, University of Padova, 35131 Padova, Italy;
| | | | - Mariapina D’Onofrio
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
| | - Michael Assfalg
- Department of Biotechnology, University of Verona, 37134 Verona, Italy; (C.G.B.); (R.T.); (F.P.); (F.M.); (M.D.)
- Correspondence:
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Hooper C, De Souto Barreto P, Payoux P, Salabert AS, Guyonnet S, Andrieu S, Sourdet S, Delrieu J, Vellas B. Association of Cortical β-Amyloid with Erythrocyte Membrane Monounsaturated and Saturated Fatty Acids in Older Adults at Risk of Dementia. J Nutr Health Aging 2017; 21:1170-1175. [PMID: 29188876 DOI: 10.1007/s12603-017-0975-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVES We examined the relationships between erythrocyte membrane monounsaturated fatty acids (MUFAs) and saturated fatty acids (SFAs) and cortical β-amyloid (Aβ) load in older adults reporting subjective memory complaints. DESIGN This is a cross-sectional study using data from the Multidomain Alzheimer Preventive Trial (MAPT); a randomised controlled trial. SETTING French community dwellers aged 70 or over reporting subjective memory complaints, but free from a diagnosis of clinical dementia. PARTICIPANTS Participants of this study were 61 individuals from the placebo arm of the MAPT trial with data on erythrocyte membrane fatty acid levels and cortical Aβ load. MEASUREMENTS Cortical-to-cerebellar standard uptake value ratios were assessed using [18F] florbetapir positron emission tomography (PET). Fatty acids were measured in erythrocyte cell membranes using gas chromatography. Associations between erythrocyte membrane MUFAs and SFAs and cortical Aβ load were explored using adjusted multiple linear regression models and were considered significant at p ≤ 0.005 (10 comparisons) after correction for multiple testing. RESULTS We found no significant associations between fatty acids and cortical Aβ load using multiple linear regression adjusted for age, sex, education, cognition, PET-scan to clinical assessment interval, PET-scan to blood collection interval and apolipoprotein E (ApoE) status. The association closest to significance was that between erythrocyte membrane stearic acid and Aβ (B-coefficient 0.03, 95 % CI: 0.00,0.05, p = 0.05). This association, although statistically non-significant, appeared to be stronger amongst ApoE ε4 carriers (B-coefficient 0.04, 95 % CI: -0.01,0.09, p = 0.08) compared to ApoE ε4 non-carriers (B-coefficient 0.02, 95 % CI: -0.01,0.05, p = 0.18) in age and sex stratified analysis. CONCLUSION Future research in the form of large longitudinal observational study is needed to validate our findings, particularly regarding the potential association of stearic acid with cortical Aβ.
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Affiliation(s)
- C Hooper
- Claudie Hooper, Gérontopôle, Department of Geriatrics, CHU Toulouse, Purpan University Hospital, Toulouse, France. , Tel : +33 (5) 61 77 64 25, Fax : +33 (5) 61 77 64 75
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7
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Kokjohn TA, Maarouf CL, Daugs ID, Hunter JM, Whiteside CM, Malek-Ahmadi M, Rodriguez E, Kalback W, Jacobson SA, Sabbagh MN, Beach TG, Roher AE. Neurochemical profile of dementia pugilistica. J Neurotrauma 2013; 30:981-97. [PMID: 23268705 PMCID: PMC3684215 DOI: 10.1089/neu.2012.2699] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Dementia pugilistica (DP), a suite of neuropathological and cognitive function declines after chronic traumatic brain injury (TBI), is present in approximately 20% of retired boxers. Epidemiological studies indicate TBI is a risk factor for neurodegenerative disorders including Alzheimer disease (AD) and Parkinson disease (PD). Some biochemical alterations observed in AD and PD may be recapitulated in DP and other TBI persons. In this report, we investigate long-term biochemical changes in the brains of former boxers with neuropathologically confirmed DP. Our experiments revealed biochemical and cellular alterations in DP that are complementary to and extend information already provided by histological methods. ELISA and one-dimensional and two dimensional Western blot techniques revealed differential expression of select molecules between three patients with DP and three age-matched non-demented control (NDC) persons without a history of TBI. Structural changes such as disturbances in the expression and processing of glial fibrillary acidic protein, tau, and α-synuclein were evident. The levels of the Aβ-degrading enzyme neprilysin were reduced in the patients with DP. Amyloid-β levels were elevated in the DP participant with the concomitant diagnosis of AD. In addition, the levels of brain-derived neurotrophic factor and the axonal transport proteins kinesin and dynein were substantially decreased in DP relative to NDC participants. Traumatic brain injury is a risk factor for dementia development, and our findings are consistent with permanent structural and functional damage in the cerebral cortex and white matter of boxers. Understanding the precise threshold of damage needed for the induction of pathology in DP and TBI is vital.
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Affiliation(s)
- Tyler A. Kokjohn
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
- Department of Microbiology, Midwestern University School of Medicine, Glendale, Arizona
| | - Chera L. Maarouf
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
| | - Ian D. Daugs
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
| | - Jesse M. Hunter
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
| | - Charisse M. Whiteside
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
| | - Michael Malek-Ahmadi
- Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, Arizona
| | - Emma Rodriguez
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
- National Institute of Cardiology, Mexico City, Mexico
| | - Walter Kalback
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
| | - Sandra A. Jacobson
- Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, Arizona
| | - Marwan N. Sabbagh
- Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, Arizona
| | - Thomas G. Beach
- Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Sun City, Arizona
| | - Alex E. Roher
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona
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Maarouf CL, Daugs ID, Kokjohn TA, Walker DG, Hunter JM, Kruchowsky JC, Woltjer R, Kaye J, Castaño EM, Sabbagh MN, Beach TG, Roher AE. Alzheimer's disease and non-demented high pathology control nonagenarians: comparing and contrasting the biochemistry of cognitively successful aging. PLoS One 2011; 6:e27291. [PMID: 22087282 PMCID: PMC3210154 DOI: 10.1371/journal.pone.0027291] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 10/13/2011] [Indexed: 12/13/2022] Open
Abstract
The amyloid cascade hypothesis provides an economical mechanistic explanation for Alzheimer's disease (AD) dementia and correlated neuropathology. However, some nonagenarian individuals (high pathology controls, HPC) remain cognitively intact while enduring high amyloid plaque loads for decades. If amyloid accumulation is the prime instigator of neurotoxicity and dementia, specific protective mechanisms must enable these HPC to evade cognitive decline. We evaluated the neuropathological and biochemical differences existing between non-demented (ND)-HPC and an age-matched cohort with AD dementia. The ND-HPC selected for our study were clinically assessed as ND and possessed high amyloid plaque burdens. ELISA and Western blot analyses were used to quantify a group of proteins related to APP/Aβ/tau metabolism and other neurotrophic and inflammation-related molecules that have been found to be altered in neurodegenerative disorders and are pivotal to brain homeostasis and mental health. The molecules assumed to be critical in AD dementia, such as soluble or insoluble Aβ40, Aβ42 and tau were quantified by ELISA. Interestingly, only Aβ42 demonstrated a significant increase in ND-HPC when compared to the AD group. The vascular amyloid load which was not used in the selection of cases, was on the average almost 2-fold greater in AD than the ND-HPC, suggesting that a higher degree of microvascular dysfunction and perfusion compromise was present in the demented cohort. Neurofibrillary tangles were less frequent in the frontal cortices of ND-HPC. Biochemical findings included elevated vascular endothelial growth factor, apolipoprotein E and the neuroprotective factor S100B in ND-HPC, while anti-angiogenic pigment epithelium derived factor levels were lower. The lack of clear Aβ-related pathological/biochemical demarcation between AD and ND-HPC suggests that in addition to amyloid plaques other factors, such as neurofibrillary tangle density and vascular integrity, must play important roles in cognitive failure.
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Affiliation(s)
- Chera L. Maarouf
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Ian D. Daugs
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Tyler A. Kokjohn
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
- Department of Microbiology, Midwestern University, Glendale, Arizona, United States of America
| | - Douglas G. Walker
- Laboratory of Neuroinflammation, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Jesse M. Hunter
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Jane C. Kruchowsky
- Laboratory of Neuroinflammation, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Randy Woltjer
- Department of Pathology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Jeffrey Kaye
- Layton Aging and Alzheimer's Disease Center, Department of Neurology, Oregon Health and Science University, United States of America
| | | | - Marwan N. Sabbagh
- Cleo Roberts Center for Clinical Research, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Thomas G. Beach
- Civin Laboratory for Neuropathology, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
| | - Alex E. Roher
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, Arizona, United States of America
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Kim J, Park YJ, Jang Y, Kwon YH. AMPK activation inhibits apoptosis and tau hyperphosphorylation mediated by palmitate in SH-SY5Y cells. Brain Res 2011; 1418:42-51. [PMID: 21937027 DOI: 10.1016/j.brainres.2011.08.059] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Revised: 08/16/2011] [Accepted: 08/23/2011] [Indexed: 11/25/2022]
Abstract
Obesity and diabetes have been shown to be associated with cognitive impairment or early neurodegeneration. However, the cellular mechanisms that link between these two pathologies have not been clarified. In this study, we treated SH-SY5Y human neuroblastoma cells with palmitate and observed its effect on cell apoptosis and tau hyperphosphorylation. Dose- and time-dependent effects of palmitate on apoptosis were observed. Palmitate treatment induced endoplasmic reticulum (ER) stress, determined by the expression of spliced X-box binding protein 1 (XBP-1) mRNA and immunoglobin heavy chain-binding protein (BiP). We also observed increases in c-Jun N-terminal kinase (JNK) activation and tau hyperphosphorylation in response to palmitate. Although palmitate did not impair insulin signaling as shown by the immunoblotting analysis of AKT phosphorylation, it did inactivate AMP-activated protein kinase (AMPK). Activation of AMPK by N(1)-(β-d-Ribofuranosyl)-5-aminoimidazole-4-carboxamide (AICAR), significantly reduced the apoptosis of cells treated with palmitate. AICAR also significantly inhibited ER stress, resulting in reduced tau hyperphosphorylation in cells treated with palmitate. Similarly, A769662, a direct activator of AMPK, also abolished the ER stress-mediated apoptosis and tau hyperphosphorylation. Therefore, these data suggest that palmitate triggers ER stress-mediated lipotoxicity and that AMPK activation inhibits apoptosis and tau hyperphosphorylation mediated by palmitate in SH-SY5Y cells.
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Affiliation(s)
- Juhae Kim
- Department of Food and Nutrition, Seoul National University, 599 Gwanak-ro, Gwanak-Gu, Seoul, 151-742, Republic of Korea
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10
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Abstract
Diets rich in SFA have been implicated in Alzheimer's disease (AD). There is strong evidence to suggest that microglial activation augments the progression of AD. However, it remains uncertain whether SFA can initiate microglial activation and whether this response can cause neuronal death. Using the BV-2 microglial cell line and primary microglial culture, we showed that palmitic acid (PA) and stearic acid (SA) could activate microglia, as assessed by reactive morphological changes and significantly increased secretion of pro-inflammatory cytokines, NO and reactive oxygen species, which trigger primary neuronal death. In addition, the mRNA level of these pro-inflammatory mediators determined by RT-PCR was also increased by PA and SA. We further investigated the intracellular signalling mechanism underlying the release of pro-inflammatory mediators from PA-activated microglial cells. The present results showed that PA activated the phosphorylation and nuclear translocation of the p65 subunit of NF-κB. Furthermore, pyrrolidine dithiocarbamate, a NF-κB inhibitor, attenuated the production of pro-inflammatory mediators except for IL-6 in PA-stimulated microglia. Administration of anti-Toll-like receptor (TLR)4-neutralising antibody repressed PA-induced NF-κB activation and pro-inflammatory mediator production. In conclusion, the present in vitro study demonstrates that SFA could activate microglia and stimulate the TLR4/NF-κB pathway to trigger the production of pro-inflammatory mediators, which may contribute to neuronal death.
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11
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Wang DC, Sun CH, Liu LY, Sun XH, Jin XW, Song WL, Liu XQ, Wan XL. Serum fatty acid profiles using GC-MS and multivariate statistical analysis: potential biomarkers of Alzheimer's disease. Neurobiol Aging 2010; 33:1057-66. [PMID: 20980076 DOI: 10.1016/j.neurobiolaging.2010.09.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 09/02/2010] [Accepted: 09/16/2010] [Indexed: 11/15/2022]
Abstract
Previous studies showed the relationship between fatty acids and the risk of developing Alzheimer's disease (AD). However, they did not address potential differences in free fatty acid (FFA) profiles that could be used to distinguish between AD patients and healthy controls. In the present study we used gas chromatography-mass spectrometry (GC-MS) technology coupled with multivariate statistical analysis to study profiles of FFA in AD. The results indicated 2 saturated fatty acids (C14:0 and C16:0; p < 0.001 and p < 0.05, respectively), 3 unsaturated fatty acids (C18:1, C18:3, and C22:6; p < 0.05, p < 0.05, and p < 0.001, respectively), where mean levels in serum from AD patients were significantly lower than controls. Partial least squares discriminant analysis (PLS-DA) models with unit variance (UV) scaling and orthogonal signal correction (OSC) data preprocessing methods were employed to refine intergroup differences between FFA profiles. The results of the analysis have highlighted docosahexaenoic acid (DHA) as the FFA with the greatest potential as a biomarker of AD, and this study has demonstrated that FFA biomarkers have considerable potential in diagnosing and monitoring AD.
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Affiliation(s)
- De-Cai Wang
- Public Health College, Harbin Medical University, Harbin, China.
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12
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Maarouf CL, Daugs ID, Spina S, Vidal R, Kokjohn TA, Patton RL, Kalback WM, Luehrs DC, Walker DG, Castaño EM, Beach TG, Ghetti B, Roher AE. Histopathological and molecular heterogeneity among individuals with dementia associated with Presenilin mutations. Mol Neurodegener 2008; 3:20. [PMID: 19021905 PMCID: PMC2600784 DOI: 10.1186/1750-1326-3-20] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Accepted: 11/20/2008] [Indexed: 01/19/2023] Open
Abstract
Background Mutations in the presenilin (PSEN) genes are associated with early-onset familial Alzheimer's disease (FAD). Biochemical characterizations and comparisons have revealed that many PSEN mutations alter γ-secretase activity to promote accumulation of toxic Aβ42 peptides. In this study, we compared the histopathologic and biochemical profiles of ten FAD cases expressing independent PSEN mutations and determined the degradation patterns of amyloid-β precursor protein (AβPP), Notch, N-cadherin and Erb-B4 by γ-secretase. In addition, the levels of Aβ40/42 peptides were quantified by ELISA. Results We observed a wide variation in type, number and distribution of amyloid deposits and neurofibrillary tangles. Four of the ten cases examined exhibited a substantial enrichment in the relative proportions of Aβ40 over Aβ42. The AβPP N-terminal and C-terminal fragments and Tau species, assessed by Western blots and scanning densitometry, also demonstrated a wide variation. The Notch-1 intracellular domain was negligible by Western blotting in seven PSEN cases. There was significant N-cadherin and Erb-B4 peptide heterogeneity among the different PSEN mutations. Conclusion These observations imply that missense mutations in PSEN genes can alter a range of key γ-secretase activities to produce an array of subtly different biochemical, neuropathological and clinical manifestations. Beyond the broad common features of dementia, plaques and tangles, the various PSEN mutations resulted in a wide heterogeneity and complexity and differed from sporadic AD.
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Affiliation(s)
- Chera L Maarouf
- The Longtine Center for Molecular Biology and Genetics, Sun Health Research Institute, Sun City, AZ 85351, USA.
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13
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Patil S, Sheng L, Masserang A, Chan C. Palmitic acid-treated astrocytes induce BACE1 upregulation and accumulation of C-terminal fragment of APP in primary cortical neurons. Neurosci Lett 2006; 406:55-9. [PMID: 16904262 DOI: 10.1016/j.neulet.2006.07.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 06/23/2006] [Accepted: 07/08/2006] [Indexed: 01/30/2023]
Abstract
High-fat diet is a significant risk factor for the development of Alzheimer's disease (AD). In addition, the AD brain is characterized by elevated levels of fatty acids as compared to that of healthy controls. Despite this, it is unclear how elevated levels of fatty acids are related to the pathogenesis of AD. The present study examines the role of saturated fatty acid, palmitic acid (PA), in causing BACE1 upregulation and consequent amyloidogenic processing of beta-amyloid precursor protein (APP), one of the main characteristic signatures of AD pathology. Here, primary rat cortical neurons and astrocytes were treated with pathological concentration of PA. There was no change in the BACE1 levels in the rat cortical neurons treated directly with PA as compared to controls. The conditioned medium from PA-treated astrocytes, however, caused BACE1 upregulation in the cortical neurons. Moreover, there was a consequent increase in the cleavage of APP leading to the accumulation of the C-terminal fragment of APP (C99) in the cortical neurons. Co-treatment of neurons with 1,3-dimethyl urea (DMU), an antioxidant, decreased PA-induced upregulation in the levels of BACE1 and C99. The present results establish an important role of saturated fatty acids in AD-associated amyloidogenesis through astroglia-mediated oxidative stress.
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Affiliation(s)
- Sachin Patil
- Department of Chemical Engineering and Material Science, Michigan State University, East Lansing, MI-48823, USA
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14
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Gellermann GP, Appel TR, Davies P, Diekmann S. Paired helical filaments contain small amounts of cholesterol, phosphatidylcholine and sphingolipids. Biol Chem 2006; 387:1267-74. [PMID: 16972796 DOI: 10.1515/bc.2006.157] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
By using qualitative and quantitative high-performance thin layer chromatography (hpTLC) we found lipids associated with purified Alzheimer's (AD) paired helical filaments (PHF) in an amount of 1.4+/-0.2% of the total anhydrous mass. Compared to normal brain tissue these lipids have an unusual lipid class composition. The most prominent lipid classes were phosphatidylcholine (PC), cholesterol (CH), galactocerebrosides (GC) and sphingomyelin (SM). In addition, the use of micro high-performance liquid chromatography (HPLC) in combination with matrix-assisted laser desorption and ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) allowed the determination of the molecular species of the polar membrane lipid classes present in PHF. The lipid pattern of intracellular PHF shows many characteristics of the conserved lipid pattern previously described for extracellular amyloid fibrils, suggesting similarities in their pathway of formation.
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Affiliation(s)
- Gerald P Gellermann
- Leibniz Institute for Age Research, Fritz-Lipmann-Institut, Beutenbergstrasse 11, D-07745 Jena, Germany.
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15
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Patil S, Chan C. Palmitic and stearic fatty acids induce Alzheimer-like hyperphosphorylation of tau in primary rat cortical neurons. Neurosci Lett 2005; 384:288-93. [PMID: 15939536 DOI: 10.1016/j.neulet.2005.05.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Revised: 04/26/2005] [Accepted: 05/05/2005] [Indexed: 10/25/2022]
Abstract
Epidemiological studies suggest that high fat diets significantly increase the risk of Alzheimer's disease (AD). In addition, the AD brain is characterized by high fatty acid content compared to that of healthy subjects. Nevertheless, the basic mechanism relating elevated fatty acids and the pathogenesis of AD remains unclear. The present study examines the role of fatty acids in causing hyperphosphorylation of the tau protein, one of the characteristic signatures of AD pathology. Hyperphosphorylation of tau disrupts the cell cytoskeleton and leads to neuronal degeneration. Here, primary rat cortical neurons and astrocytes were treated with saturated free fatty acids (FFAs), palmitic and stearic acids. There was no change in the levels of phosphorylated tau in rat cortical neurons treated directly with these FFAs. The conditioned media from FFA-treated astrocytes, however, caused hyperphosphorylation of tau in the cortical neurons at AD-specific phospho-epitopes. Co-treatment of neurons with N-acetyl cysteine, an antioxidant, reduced FFA-induced hyperphosphorylation of tau. The present results establish a central role of FFAs in causing hyperphosphorylation of tau through astroglia-mediated oxidative stress.
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Affiliation(s)
- Sachin Patil
- Cellular and Biomolecular Laboratory, Department of Chemical Engineering and Material Science, Michigan State University, East Lansing, MI 48824, USA
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16
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Gamblin TC. Potential structure/function relationships of predicted secondary structural elements of tau. Biochim Biophys Acta Mol Basis Dis 2005; 1739:140-9. [PMID: 15615633 DOI: 10.1016/j.bbadis.2004.08.013] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Accepted: 08/30/2004] [Indexed: 01/14/2023]
Abstract
The microtubule-associated protein tau is believed to be a natively unfolded molecule with virtually no secondary structure. However, this protein self-associates into filamentous forms in various neurodegenerative diseases. Since these filamentous forms show a remarkable degree of higher order due to their regular widths and periodicity, it is widely speculated that tau does contain secondary structures that come together to form tertiary and quaternary structures in the filamentous form. The purpose of this review is to use the primary sequence of tau along with predictive methods in an effort to identify potential secondary structural elements that could be involved in its normal and pathological functions. Although there are few predicted structural elements in the tau molecule, these analyses should lead to a better understanding of the structure/function relationships that regulate the behavior of tau.
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Affiliation(s)
- T Chris Gamblin
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave. Lawrence, KS 66045, USA.
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17
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Shen Y, Lue L, Yang L, Roher A, Kuo Y, Strohmeyer R, Goux WJ, Lee V, Johnson GV, Webster SD, Cooper NR, Bradt B, Rogers J. Complement activation by neurofibrillary tangles in Alzheimer's disease. Neurosci Lett 2001; 305:165-8. [PMID: 11403931 DOI: 10.1016/s0304-3940(01)01842-0] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Brain inflammation is widely documented to occur in Alzheimer's disease (AD), but its sources are still incompletely understood. Here, we present in vitro and in situ evidence that, like amyloid beta peptide (Abeta), tau, the major protein constituent of the neurofibrillary tangle, is a potent, antibody-independent activator of the classical complement pathway. Complement activation, in turn, is known to drive numerous inflammatory responses, including scavenger cell activation and cytokine production. Because Abeta deposits and extracellular tangles are present from early preclinical to terminal stages of AD, their ability to activate complement provides a ready mechanism for initiating and sustaining chronic, low-level inflammatory responses that may cumulate over the disease course.
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Affiliation(s)
- Y Shen
- Sun Health Research Institute, 10515 West Santa Fe Drive, Sun City, AZ 85351, USA
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18
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Buée L, Bussière T, Buée-Scherrer V, Delacourte A, Hof PR. Tau protein isoforms, phosphorylation and role in neurodegenerative disorders. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2000; 33:95-130. [PMID: 10967355 DOI: 10.1016/s0165-0173(00)00019-9] [Citation(s) in RCA: 1409] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tau proteins belong to the family of microtubule-associated proteins. They are mainly expressed in neurons where they play an important role in the assembly of tubulin monomers into microtubules to constitute the neuronal microtubules network. Microtubules are involved in maintaining the cell shape and serve as tracks for axonal transport. Tau proteins also establish some links between microtubules and other cytoskeletal elements or proteins. Tau proteins are translated from a single gene located on chromosome 17. Their expression is developmentally regulated by an alternative splicing mechanism and six different isoforms exist in the human adult brain. Tau proteins are the major constituents of intraneuronal and glial fibrillar lesions described in Alzheimer's disease and numerous neurodegenerative disorders referred to as 'tauopathies'. Molecular analysis has revealed that an abnormal phosphorylation might be one of the important events in the process leading to their aggregation. Moreover, a specific set of pathological tau proteins exhibiting a typical biochemical pattern, and a different regional and laminar distribution could characterize each of these disorders. Finally, a direct correlation has been established between the progressive involvement of the neocortical areas and the increasing severity of dementia, suggesting that pathological tau proteins are reliable marker of the neurodegenerative process. The recent discovery of tau gene mutations in frontotemporal dementia with parkinsonism linked to chromosome 17 has reinforced the predominant role attributed to tau proteins in the pathogenesis of neurodegenerative disorders, and underlined the fact that distinct sets of tau isoforms expressed in different neuronal populations could lead to different pathologies.
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Affiliation(s)
- L Buée
- INSERM U422, Place de Verdun, 59045 cedex, Lille, France.
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Kuo YM, Crawford F, Mullan M, Kokjohn TA, Emmerling MR, Weller RO, Roher AE. Elevated Aβ and Apolipoprotein E in AβPP Transgenic Mice and Its Relationship to Amyloid Accumulation in Alzheimer’s Disease. Mol Med 2000. [DOI: 10.1007/bf03401785] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Appel TR, Dumpitak C, Matthiesen U, Riesner D. Prion rods contain an inert polysaccharide scaffold. Biol Chem 1999; 380:1295-306. [PMID: 10614822 DOI: 10.1515/bc.1999.165] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A polysaccharide consisting of mainly 1,4-linked glucose units was found associated with prion rods, which are composed mainly of insoluble aggregates of the N-terminally truncated prion protein (PrP 27-30) exhibiting the ultrastructural and tinctorial properties of amyloid. The polysaccharide differs in composition from the Asn-linked oligosaccharides and the GPI-anchor of the prion protein. Prion rods were prepared from scrapie-infected hamster brains using two different purification protocols. Prolonged digestion of rods with proteinase K reduced PrP by a factor of at least 500, leaving about 10% (w/w) of the sample as an insoluble remnant. Only glucose was obtained by acid hydrolysis of the remnant and methylation analysis showed 80% 1,4-, 15% 1,6- and 5% 1,4,6-linked glucose units. The physical and chemical properties as well as the absence of terminal glucose units indicate a very high molecular mass of the polysaccharide. No evidence was found for covalent bonds between PrP and the polysaccharide. The polysaccharide certainly contributes to the unusual chemical and physical stability of prion rods, acting like a scaffold. A potential structural and/or functional relevance of the polysaccharide scaffold is discussed.
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Affiliation(s)
- T R Appel
- Institut für Physikalische Biologie, Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-Universität Düsseldorf, Germany
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Affiliation(s)
- A E Roher
- Haldeman Laboratory for Alzheimer Disease Research, Sun Health Research Institute, Sun City, AZ 85351, USA.
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22
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Wang JZ, Grundke-Iqbal I, Iqbal K. Glycosylation of microtubule-associated protein tau: an abnormal posttranslational modification in Alzheimer's disease. Nat Med 1996; 2:871-5. [PMID: 8705855 DOI: 10.1038/nm0896-871] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Alzheimer's disease (AD) is characterized by the presence of numerous neurons with neurofibrillary tangles of paired helical filaments (PHFs). The microtubule-associated protein tau in abnormally hyperphosphorylated form is the major protein subunit of the PHF. We now show that PHF tangles isolated from AD brains are glycosylated, whereas no glycan is detected in normal tau. Deglycosylation of PHF tangles by endoglycosidase F/N-glycosidase F converts them into bundles of straight filaments 2.5 +/- 0.5 nm in diameter, similar to those generated by the interaction of normal tau and abnormally hyperphosphorylated tau (AD P-tau). Deglycosylation plus dephosphorylation, but not deglycosylation alone, of AD P-tau and tau from PHF tangles restores their microtubule polymerization activity. Dephosphorylation of deglycosylated PHF tangles results in increased tau release. Thus, although the abnormal phosphorylation might promote aggregation of tau and inhibition of the assembly of microtubules, glycosylation appears to be responsible for the maintenance of the PHF structure.
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Affiliation(s)
- J Z Wang
- New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York 10314, USA
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